Lubricating apparatus

ABSTRACT

Lubricating apparatus for automatically providing a constant supply of lubricant to air operated tools during the operation of such tools, including an expansible and contractible pump chamber having an intake port for connection with a supply of lubricant and a delivery port for delivering lubricant from the pump chamber to the tool being lubricated. The apparatus includes a main air passage for connection with a source of air under pressure for driving the tool, and a normally closed control valve controls flow through the main air passage and is movable to an open position to permit flow through the air passage in response to a pressure drop between the upstream and downstream sides of the valve caused by starting the tool into operation. Means operable in response to air flow through the main passage causes the pump chamber to alternately expand and contract and pump lubricant to the working parts of the tool so long as the tool is in operation. The cycle of the pump can be selectively adjusted to increase or decrease the rate of flow of lubricant to the tool.

United States Patent Callahan et al;

1151 3,693,757 1451 Sept. 26, 1972 [54] LUBRICATTNG APPARATUS [721lnventors: James J. Callahan, Mentor; John Proctor Snow, Macedonia, bothof v Ohio [73] Assignee: McCord Corporation [22] Filed: Aug. 3, 1970 21Appl. No.2 60,411

[52 us. c1....;... ..184/7 D, 184/29, 184/56 A 51 Int. Cl ..Fl6n 25/02[58] Field of Search.....l84/56 R, 56 A, 7 D, 7 F, 29,

Primary ExaminerManuel Antonakas Attorney-McGlynn, Reising, Milton &Ethington TO TOOL TO TOOL,

[ 5 7 ABSTRACT Lubricating apparatus for automatically providing aconstant supply of lubricant to air operated tools during theoperation-of such tools, including an expansible and contractible pumpchamber having an intake port for connection with a supply of lubricantand a delivery port for delivering lubricant from the pump chamber tothe tool being lubricated. The apparatus includes a main air passage forconnection with a source of air under pressure for driving the tool, anda normally closed control valve controls flow through the main airpassage and is movable to an open position to permit flow through theair passage in response to a pressure drop between the upstream anddownstream sides of the valve caused by starting the tool intooperation. Means operable in response to air flow through the mainpassage causes the pump chamber to alternately expand and contract andpump 22 Claims, 4 Drawing Figures RESERVOIR FOR LUBRiCANT $29 F fioi 25v 27 .24 45 Z /I FROM AIR SUPPLY TO TOOL PATENTEDSEPMIQ v 3,893.75?

sum 1 [IF 2 RESERVOIR R LUBRICANT TO TOOL FROM AI R j 11} SUPPLY V I /6"29 6; W 2 W 6 5 I M /f I 20 50 "r 5% 28 T 5 Q l I H z;

58 TO TOOL I 52 1 20 I VI TO TOOL y k l :l

f FROM AIR Z3 {5 w SUPPLY 97;, Z INVENTORS 9 T T 1 \[zmes fa/z/lan 5 BY5/212 P5120111 ATTORNEYS PAIENTEDSEPz I912 3,693,757

SHEET 2 OF 2 7 50 5:2 I 2925 I) 5 a 26 2o 7 5 I 15 5a 5 w I 66 55 r 5;56 TO TOOL 8 f 10 TO TOOL FROM AIR 3 ,5 I? 5 SUPPLY TO TOOL I 4 1 m 35my 2? $9 INVENTORS James JTzzI/a/zan 5 fr/in 522oa/ ATTORNEYS the tool,

LUBRICATING APPARATUS This invention relates generally to lubricatingapparatus,.and is particularly concerned with apparatus forautomatically providing a constant supply of lubricant to air operatedtools, valves, cylinders and other devices during their operation.

Numerous tools are used in shops and manufacturing plants and throughoutvarious industries that are powered by. pneumatic motors from sources ofcompressed air. For proper operation of such tools, it is of coursenecessary to provide adequate lubrication for certain parts of the toolitself, and in some cases, such as drills and the like, it is necessaryto provide lubrication between the tool and the workpiece beingoperated-upon by .the tool.-

An object of this invention is to provide lubricating apparatus for airoperated tools and other air operated devices that can be connected intothe compressed air supply of such tool and operated therebysimultaneously with the operation of the tool to constantlyAnotherobject is to provide lubricating apparatus for air operated toolsand other air operated devices which can be powered by the air supplyfor the tool and automatically sitarts into" operation upon operation ofi d which is self-cycling and is selectively .a djustable in itslubricant delivery rate.

In achievement of the foregoing, and other-objects, lubricatingapparatus according to ,the present invention includes an expansible and'contractible pump chamber having an intake port for connection with asupply of lubricant and a delivery port for delivering lubricant fromthe pump chamber. The apparatus is formed, with a main air passage forconducting compressed air to the tool for operating the tool. Themainair passage has an inlet end for connection with a source of air underpressure and an outlet for connection with an air operated tool. Anormally closed control-valve controls flow through the. main airpassage and is movable to an open position when the pressure on theoutlet side of the control valve drops when the tool starts intooperation. In accordance with the invention, the flow of air through themain passage past the control'valve causes the pump chamber toalternately expand and contract and pump lubricant to the tool beingoperated by the compressed air. v

The pump chamber for the lubricant is caused to alternately expand andcontract in accordance with the contraction-and expansion, respectively,of a working chamber which is supplied air from the main passage onlywhen the control valve is open to permit flow through the main airpassage. Mechanism in the working chamber in the form of a reciprocatingpiston and a control plunger responds to flow of air into the workingchamber from the main air passage to cause the working chamber toalternately expand and con- Other objects, advantages and features ofthe inven tion will become apparent from the following description takenin connection with the accompanying drawing in which:

FIGS. 1 through 4 are sectional, diagramatic views of apparatusembodying the invention and sequentially illustra'ting the position ofthe-parts during a cycle of operation. 1

In the drawings, reference numeral 2 collectively designatesa body forhousing part of the mechanismof the lubricating apparatus, and referencenumeral 4 collectively designates a base member for housing control andsupply valves for the apparatus, and which is attached to the body 2 bybolts or other conventional means. Formed in the body 2 is an expansibleand contractible pump chamber 6 having an intake port 3 for connectionwith a supply of lubricant in a container or reservoir 7 through apassage 3a and a delivery port 5 for delivering lubricant from the pumpchamber through a passage 5a. A main air passage 8 is formed in body 2having an inletend 10 for connection with a source of air underpressure, and an outlet end 12 for connection with an air operated toolor the like through any suitable connection such as a flexible hose. Anormally closed control valve 14 is mounted in the main passage in acontrol valve chamber 13 and is caused to move to an open position andpermit flow through passage 8 in response to a pressure drop between theinlet 10 and outlet 12 upon demand by the tool being driven by thecompressed air. Control valve 14 is biased to a closed position by aspring 17. Reference numeral 16 collectively designates means operablein response to flow through the main passage 8 past valve 14 to causethepump chamber 6 to alternately expand and contract to deliver lubricantthrough passage 5a to the tool being driven by the supply of air throughpassage 8.

Formed in body 2 is a cylindrical bore 18. The open end of bore 18 isclosed by an end wall member 20 which is secured in position by a snapring 22 or other conventional means. Reciprocably mounted in bore 18 isa piston member 24, one face 25 of which cooperates with the end wallmember 20 to define an expansible and contractible working chamber 26.Piston 24 is provided with a sealing member 23 for engaging the sidewall of bore 18. An exhaust chamber 27 is defined on the side of piston24 opposite'the working chamber 26 and is connected through a port 29with ambient atmosphere.

Slidably mounted in a central cylindrical opening of the end wall member20 is a control plunger 28 which is operable to cause the workingchamber 26 to vent and contract when the volume of the working chamber26 exceeds a predetermined maximum. The control plunger has a stemportion 30 slidably mounted in the central opening of the end wallmember 20, and an enlarged end portion 32 is formed on the stem portion30 and is received in the working chamber 26.

The right hand face 25 of piston 24 defines a movanient '40 whichengages the rear or trailing face 38 of v the end portion 32 to maintaina space for fluid between the end wall and the portion of face 38 thatprojects beyond the abutment and is actedagainst by the pressure in'theworking chamber 26.

A vent port 42 is formed in the control plunger 28, one end of the ventport communicating with a recess in face 36.o f the end portion 32, andthe other end of the vent port communicating at44 with a surface of thecontrol plunger 28 at a location spaced from face 36 a distance suchthat the other end 44 is uncovered by the end wall member 20 tocommunicate with atmosphere only whenthe face 38 of the end portion 32is engaged with the abutment member 40, Transversely mounted in the stem30 of plunger 28 is a stop pin 46 for limiting the travel of the plungertoward the left, as viewed in the drawing, due to the engagement of pin46 with an abutment 47 projecting from the outer surface of end wallmember 20. v v

.A supply port 48 for the working chamber 26 is connected with the mainair passage 8 by a supply passage 50. Flow through the supply passage 50is controlled by a normally closed supply valve 52 received in a supplyvalve chamber 57, and which moves to an open position only in responseto fluid flow in the main passage 8. The rate of flow of fluid into-theworking chamber 26 is determinedby the position of an adjustable needlevalve 54. l

The supply valve 52 is biased to a closed position by a spring 55 toprevent flow through supply passage 50, and the annular front face 52aof valve 52 is subjected to the pressure from air passage 8 on the inletside of control valve 14 through a branch passage 56, and the rear face52b of valve 52 is subjected to the pressure from main passage 8 on theoutlet side of control valve 14 through a branch passage 58.Consequently, when the pressure in passage 8 between outlet 12 andcontrol valve 14 (or on the outlet or downstream side of control valve14) drops due to the tool or other air driven device being brought intooperation, the reduced pressure in the outlet portion of passage 8 issensed through branch passage 58 by the supply valve 52. Thus, thepressure drop across control valve 14 when air flows through the mainpassage 8 also causes the supply valve 52 to move to an open positionand admit air through supply passage 50 past the needle valve 54 to theworking chamber'ZtS.

The cylindrical bore 18 is stepped with a reduced portion 60 located onthe opposite side of piston 24 from the working chamber, and the piston24 has a reduced portion 62 which projects into the reduced portion 60of the bore. Mounted on the reduced portion 62 is a sealing member 65which slidably engages the side wall of the reduced portion 60 of thebore. The end wall of the reduced portion of the bore cooperates withthe end of the reduced portion 62 of the piston to define a returnpressure chamber 63. Chamber 63 is connected through a port 64 and areturn pressure branch passage 66 with the outlet side of the mainpassage 8.

The intake port 3 of the pumping chamber 6 is connected with thelubricant container 7, and the passage 3a between intake port 3 and thelubricant container 7 is controlled by a check valve 70 which permitsflow from the lubricant container 7 to the pumping chamber 6, butprevents flow in the opposite direction. The delivery port 5 of thepumping chamber 6- is connected with the parts to be lubricated of thetool or other device being operated by the supply of air through passage8, and a check valve 72 in passage 5a permits the lubricant to bedelivered from the pumping chamber '6 through the delivery port 5, butprevents flow in the opposite direction. A pump plunger 68 is mounted inchamber 6 and moves toward the left against a spring 69 to contract thepumpingchamber6, the spring 69 biasing the plunger 68 to the positionshown in FIG. 1 to expand chamber 6.

Chamber 6 is defined by a cylindrical housing or plug member 76 insertedinto the large diameter portion of a stepped diameter cylindrical bore71 formed in the body 2 in coaxial relationship with the cylindricalbore 18. The stem of plunger 68 is mounted in a cylindrical bearing 74received in the small diameter portion of bore 71 and projects throughan opening between the coaxial bores into the low pressure chamber 63.Thus, the plunger stem 68 is engageable by the reduced portion 62 ofpiston 24.

FIG. 1 illustrates the position of the parts when there is no air flowthrough passage 8 such as would be the case when the tool or otherdevice connected with the air passage 8 is not in operation. The outlet12 of passage 8 may be connected with the air driven motor of the toolto be operated either directly or by a flexible hose or the like, andthe discharge passage 5a from the lubricant pumping chamber 6 maysimilarly be connected with the part or parts to be lubricated. When thetool is not in operation, the pressure in passage 8 on the inlet andoutlet sides of control valve 14 is the same, and control valve 14 is inits closed position due to spring 17 so that there is no flow throughpassage 8.

Pressure on the outlet portion of passage 8 acts through branch passage66 in chamber 63 on the reduced portion 62 of piston 24 to urge piston24 to the right to the position shown in FIG. 1 to place the workingchamber 26 in a contracted condition of minimum volume. Since thepressure in chamber 63 acts on the reduced portion 62 of piston 24 tourge the piston toward the right, the working chamber 26 can expand onlywhen the pressure in the working chamber 26 acting against face 25 ofpiston 24 is suflicient to exert a force on piston 24 greater than theforce exerted by the pressure in chamber 63.

When the tool is brought into operation, the pressure on the outlet sideof the main passage 8 drops due to the demand of the tool, and theresulting pressure differential on control valve 14 causes the controlvalve 14 to move to an open position as shown in FIG. 2 permittingcontinuous flow through passage 8. The reduced size of the T-shapedpassage 15 of control valve 14 with respect to the size of the inletside of passage 8 provides a pressure drop across valve 14 which servesto hold the valve in an open position. The pressure drop across valve 14is sensed by supply valve 52 through branch passages 56 and 58, andvalve 52-is thus moved to an open position by the pressure differentialto permit flow from the inlet side of passage 8 through branch passage56 and the supply passage 50 to the working chamber 26.

When i the pressure in chamber 26 exceeds a predetermined referencepressure, that is, the pressure sufficient to overcome the pressureinchamber 63 acton the right-hand face 25 of piston 24. As plunger 28moves toward the left, the end 44 of vent port 42 moves out ofcommunication with atmosphere and is closed by the surrounding wallportion of the central opening through end wall member 20. As shown inFIG. 2, movement of the parts toward the left causes the reduced endportion 62' of piston 24 to engage plunger 68 to thereby begincontracting the pumping chamber The control plunger 28 remains inengagement with the movable wall 25 and moves with wall 25 until pin 46engages the raised abutment 47 as shown in FIG. 3. In this position,plunger 28 is at the end of its stroke due to the engagement of pin 46with the end wall member 20, but piston 24 has not yet reached the endof its stroke and continues to move so that, piston 24 separates fromplunger 28. In the position of the parts shown in FIG. 3, pump chamber 6is substantially in its fully contracted position and has expelledlubricant from the pump chamber through delivery port 5 past check valve72.

When piston 24 separates from plunger 28, the front face 36 of plunger28 is immediately exposed to the pressure in chamber 26, which acts toreturn plunger 28 toward the right, as viewed in the drawings, until therear face 38 engages the abutment 40 as shown in FIG. 4. As soon asplunger 28 returns to the position of FIG. 4, the pressure in chamber 26is vented through vent port 42 since theend 44 of vent port 42 has againbeen brought into communication with atmosphere. The pressure in chamber63, being greater than atmospheric pressure, acts on the reduced portion62 of the piston to return the piston to the start position of FIG. 1and to therefore contract chamber 26 to its fully contracted condition.Spring 69 causes plunger 68 to return to the position of FIG. 1, whichmovement of plunger 68 causes additional lubricant to be drawn pastcheck valve 70 into the pumping chamber 6.

respondingly decreased.

As soon as the sealing pad 34 closes vent port 42, another expansioncycle begins. The cycle of expansion and contraction of chamber 26 isrepeated so long as air flows through the main passage 8. When flowthrough passage 8 stops, the pressure on both sides of control valve 14is equalized and the control valve moves to its closed position. Thisaction is of course followed by the clos'ing of supply valve 52 to shutdown the operation of the apparatus. The apparatus automatically startsinto operation upon operation of the air driven tool or other deviceconnected with main passage 8, and automatically shuts down whenoperation of the tool ceases.

The adjustable needle valve 54 controls the rate of delivery oflubricant to the tool. By increasing the rate of flow through supplypassage 50, the cycling rate is increased, and conversely, by decreasingthe rate of flow through supply passage 50, the cycling rate is'cor-Thus, the lubricating apparatus shown in the drawings includes anexpans'ible and contractible pump chamber 6 having an intake port 3 forconnection with a supply of lubricant and a delivery port 5 fordelivering lubricant from pump chamber 6; a main passage 8 having aninlet 10 for connection with a source of air under pressure and anoutlet 12 for connection with an air operated tool or the like; anormally closed control valve 14 controlling flow through the mainpassage 8 and movable to an open position in response to a pressure dropbetween inlet 10 and outlet 12 to permit flow through the main passage8; and means 16 operable in response to flow through the main passage tocause the pump chamber 6 to alternately expand and contract; and means54 for selectively varying the rate of expansion and contraction of pumpchamber 6 during flow through main passage 8.

The means 16 operable to cause the pump chamber 6'to alternately expandand contract comprises a working chamber 26 and mechanism 24, 28 forcausing the working chamber to alternately expand and contract inresponse to flow through passage 8. The control plunger 28 of themechanism is operable to cause the working chamber 26 to vent andcontract when the volume of the working chamber exceeds a maximumdetermined by the engagement of pin 26 with the end wall member 20.

While one specific form of the invention has been illustrated anddescribed in the foregoing specification and accompanying drawings, itshould be understood that the invention is not limited to the exactconstruction shown. Alterations and variations in the construction andarrangement of parts, all falling within the scope and spirit of theinvention, will be apparent to those skilled in the art.

We claim:

I. Lubricating apparatus comprising: means defining a working chamberhaving a supply port for connection with a source of fluid pressure;means defining a pressure responsive wall for said working chamberoperable to expand the working chamber from a contracted condition ofminimum volume when the pressure in the working chamber is greater thana predetermined reference pressure, and to contract the chamber to saidcontracted condition when the pressure in said pressure chamber is lessthan said reference pressure; a

control plunger mounted in said working chamber, said control plungerbeing engageable with said movable wall whenthe working chamber is inthe retracted condition and movable with said movable wall when thepressure in said working chamber is greater than the reference pressureuntil the volume of the working chamber exceeds a predetermined maximum;a vent port connecting said working chamber with a pressure less thanthe reference pressure only when said control plunger is disengaged fromsaid movable wall; a main body portion having a cylindrical bore formedtherein; an end wall member closing the open end of said bore; saidmovable wall being received in said bore and cooperating with said endwall member to define said working chamber; a piston reciprocablymounted in said bore, one face of said piston defining said movablewall; said control plunger including a stem portion slidably' mounted insaid end wall member; an enlarged endportion formed'on said stem'andreceived in said working chamber, said enlarged end portion having aleading-face engageable with said one face of said piston and a1trailingface projecting generally. radially outwardly fromsaid stem portion andsubject to the pressure in said working chamber when said leading faceis engaged withfsaid one face of said piston; an abutment projectingfrom said end wall into said working chamber for engaging said trailingfaceto maintain a space for fluidbetween said end wall and at least aportion of. said trailing face; said vent port being formed in saidcontrol plunger with one end of said vent port communicating with saidleading face and the other end of said vent port communicating with asurface of said control plunger at a location spaced from said one end adistance such that said other end is uncovered by said end wall memberonly when said trailing face is engaged with said abutment member; aresilient sealing member secured to said one face of said piston-forengagement by said leading-face of said control plunger to seal off saidvent port from said working chamber; stop means for limiting the travelof said plunger with saidpiston and causing the plunger to disengagefrom said piston when the volume of the working chamber exceeds thepredetermined maximum; said stop means comprising a stop pin mounted inthe stern of saidplunger onthe opposite side of said end wall from saidworking chamber and engageable with said 'end wall member; a mainpassage for conducting fluid under pressure from a source to a fluidpressure operated device; a supply passage connecting saidmain passagewith the supply port of said working chamber; means operable to permitflow through said supply passage only in response to fluid flow throughsaid main passage; said last named means including a normally closedcontrol valve in said main passage movable to an open position inresponse to a decrease in the pressure on the downstream side of saidcontrol valve with respect to the pressure on the upstream side of saidcontrol valve; a normally closed supply valve in said supply passagemovable to an open position in response to fluid flow through the mainpassage past. said control valve; means in said supply passage foradjustably restricting the flow through said supply passage to saidworking chamber; a return pressure branch passage connecting thedownstream portion of said main passage with said bore on the oppositeside of said piston from said working chamber; said bore being steppedwith areduced portion located on the opposite side of said piston fromsaid working chamber, said piston having a reduced portion projectinginto the reduced portion of said bore, the reduced portion of said borehaving an end wall cooperable with the reduced portion of said piston todefine a return pressure chamber, said return pressure branch passageextending between said return pressure chamber and said main passagesuch that pressure in said return pressure chamber urges said piston inthe opposite direction to the pressure in said working chamber; apumping chamber having an intake port adapted to be connected with asupplyof lubricant and a delivery port, and means operable to expand andcontract said pumping chamber in response to movement of said piston insaid bore.

2. Lubricating apparatus as claimed in claim 1 including a check valvecontrolling said intake port movable to an open position in response'toexpansion of said pump chamber to permit lubricant to be drawn into saidpump chamber and movable to a closed position in response to contractionof said pump chamber; and a check valve controlling said delivery portmovable to an open position upon contraction of said pump chamber topermit lubricantto be delivered from said pump chamber, and movable to aclosed position in response to expansion of said pump chamber.

3. Lubricating apparatus as claimed in claim 2 including a pumpingplunger reciprocably mounted in said pump chamber and connected withsaid piston for expanding 'and contracting said pump chamber in responseto contraction and expansion, respectively, of said working chamber.

4. Lubricating apparatus as claimed in claim 3 wherein said pumpingplunger has a stem projecting into said return pressure chamber forengagement by said piston, and further including a spring in said pumpchamber biasing said pumping plunger to a position in which the pumpchamber is expanded.

5. Lubricatingapparatus comprising: an expansible and contractible pumpchamber having an intake port for connection with a supply of lubricantand a delivery port for delivering lubricant from said pump chamber; amain passage having an inlet for connection with a source of air underpressure and an outlet for connection with an air operated tool or thelike; a normally closed control valve controlling flow through said mainpassage and movable to an open position in response to a pressure dropbetween said inlet and outlet to permit flow through said main passage;and means operable in response to flow through said main passage tomechanically expand and contract said pump chamber continuously duringthe time that air flows through said main passage past said controlvalve.

6. Lubricating apparatus as claimed in claim 5 further including meansfor selectively varying the rate of expansion and contraction of saidpump chamber during flow through said main passage.

7. Lubricating apparatus as claimed in claim 5 wherein said meansoperable to cause the pump chamber to alternately expand and contractcomprises a working chamber and mechanism for causing said workingchamber to alternately expand and contract in response to flow throughsaid main passage.

8. Lubricating apparatus as .claimed in claim 7 including a cylindricalbore with an end wall member closing the open end thereof; and whereinsaid mechanism includes a piston in said bore cooperable with said endwall member to define said working chamber, said piston being movabletoward and away from said end wall member-to respectively contract andexpand said working chamber.

9. Lubricating apparatus as claimed in claim 8' wherein said mechanismincludes a control plunger mounted in said end wall member operable tocause said working chamber to vent and contract when the volume of theworking chamber exceeds a predetermined maximum. l

10. Lubricating apparatus as claimed in claim 8 wherein said controlplunger has a stem portion slidably mounted in said end wall member andan enlarged end portion formed on said stem and received in said workingchamber and engageable with said piston.

11. Lubricating apparatusas claimed in 'claim7 including asupply portfor 'said working chamber; a

supply passage connecting said supply'port with said main passage; and;means operable to permit flow through said supply passage only. inresponse to fluid flow in said mainpassage. v

l2. Lubricating apparatus as claimed in claim 11 wherein saidlast namedmeansincludes a normally closed supply valve controlling said supplypassage and movable to an open position in response to fluid flowthrough said mainpassage past said control valve.

l3. Lubricating apparatus as claimed in claim 12 further including meansfor selectively varying the rate of expansion and contraction of saidpump chamber during flow through said main passage. "l4. Lubricatingapparatus as claimedin claim 13 wherein said last named means comprisesa needle valve in said supply passage adjustable to vary the rate offlow through said supply passage.

' l5. Lubricating apparatus comprising: a base member formed with a mainair passage having an inlet for connection with a source of air underpressure and an outletfor connection with an air driven tool or thelike; a normally closed control valve between said inlet and outletcontrolling flow through said main passage and movable to an openposition in response to a pressure drop between said inlet and outlet topermit flow through said main passage; a supply valve chamber formed insaid base member; a supply passage formed in said base member having oneend in communication with said supply valve chamber; a first branchpassage connecting said supply valve chamber with said control valve anda second branch passage connecting the supply valve chamber with thebranch chamber between the outlet and said control valve; a supply valvereceived in said supplyvalve chamber and having an open position topermit flow between said one branch passage and said supply passage anda closed position to shut off communication between said one branchpassage and said supply passage; said supply valve being biased to itsclosed position and responsive to a decrease in pressure in said secondbranch passage with respect to the pressure in said first branch passageto move to its open position; a return pressure passage formed in saidbase member communicating at one end with said main passage between theoutlet and control valve; a body member attached to said base member; apump chamber formed in said body member; a bore formed in said bodymember connected with the supply passage in said base member; and meansin said bore operable in response to flow through said supply passage tocause said pump chamber to alternately ex pand and contract.

16. Lubricating apparatus comprising: an expansible and contractiblepump chamber having an intake port for connection with a supply oflubricant and a delivery port for delivering lubricant from said pumpchamber; a main passage having an inlet for connection with a source ofair under pressure and an outlet for connection with an air operatedtool or the like; a normally closed control valve controlling flowthrough said main passage and movable-to an open position in response toa pressure drop between said inlet and said outlet to permit flowthroughsaid main passage; means operable in response to flow throughsaid main passage to cause said pump chamber to alternately expand andcontract; said last named means comprising a working chamber andmechanism for causing said working chamber to alternately expand andcontract in response to flow through said main passage; acylindricalbore with an end wall member closing the open endthereof; said mechanismincluding a piston in said bore cooperable with said end wall member todefine said working chamber, said piston being movable toward and awayfrom said end wall member to respectively contract and expand saidworking chamber; said control plunger having a stem portion slidablymounted in said end wall member and an enlarged end portion formed onsaid stem and received in said working chamber and engageable with saidpiston, one face of said piston defining a movable wall for said workingchamber; the enlarged end portion of said control plunger having aleading face engageable with said one face of said piston and a trailingface projecting generally radially outwardly from said stem portion andsubject to expanding pressure in said working chamber when said leadingface is engaged with said one face of said piston.

17. Lubricating apparatus as claimed in claim 16 including an abutmentprojecting from said end wall member into said'working chamber forengaging said trailing face to maintain a space for fluid between saidend wall and at least a portion of said trailing face.

18. Lubricating apparatus as claimed in claim 17 wherein a vent port isformed in said control plunger and one end of said vent portcommunicates with said leading face.

19. Lubricating apparatus as claimed in claim 18 wherein the other endof said vent port communicates with a surface of said control plunger ata location spaced from said one end a distance such that said other endis uncovered by said end wall member only when said trailing face isengaged with said abutment member.

20. Lubricating apparatus as claimed in claim 19 including a resilientsealing member secured to said one face of said piston for engagement bysaid leading face of said control plunger to seal off said vent portfrom said working chamber.

21. Lubricating apparatus as claimed in claim 19 including stop meansfor limiting the travel of said plunger with said piston and causing theplunger to disengage from said piston when the volume of the workingchamber exceeds the predetermined maximum.

22. Lubricating apparatus as claimed in claim 21 wherein said stop meanscomprises a stop pin mounted in the stem of said plunger on the oppositeside of said end wall from said working chamber and engageable with saidend wall member.

1. Lubricating apparatus comprising: means defining a working chamberhaving a supply port for connection with a source of fluid pressure;means defining a pressure responsive wall for said working chamberoperable to expand the working chamber from a contracted condition ofminimum volume when the pressure in the working chamber is greater thana predetermined reference pressure, and to contract the chamber to saidcontracted condition when the pressure in said pressure chamber is lessthan said reference pressure; a control plunger mounted in said workingchamber, said control plunger being engageable with said movable wallwhen the working chamber is in the retracted condition and movable withsaid movable wall when the pressure in said working chamber is greaterthan the reference pressure until the volume of the working chamberexceeds a predetermined maximum; a vent port connecting said workingchamber with a pressure less than the reference pressure only when saidcontrol plunger is disengaged from said movable wall; a main bodyportion having a cylindrical bore formed therein; an end wall memberclosing the open end of said bore; said movable wall being received insaid bore and cooperating with said end wall member to define saidworking chamber; a piston reciprocably mounted in said bore, one face ofsaid piston defining said movable wall; said control plunger including astem portion slidably mounted in said end wall member; an enlarged endportion formed on said stem and received in said working chamber, saidenlarged end portion having a leading face engageable with said one faceof said piston and a trailing face projecting generally radiallyoutwardly from said stem portion and subject to the pressure in saidworking chamber when said leading face is engaged with said one face ofsaid piston; an abutment projecting from said end wall into said workingchamber for engaging said trailing face to maintain a space for fluidbetween said end wall and at least a portion of said trailing face; saidvent port being formed in said control plunger with one end of said ventport communicating with said leading face and the other end of said ventport communicating with a surface of said control plunger at a locationspaced from said one end a distance such that said other end isuncovered by said end wall member only when said trailing face isengaged with said abutment member; a resilient sealing member secured tosaid one face of said piston for engagement by said leading face of saidcontrol plunger to seal off said vent port from said working chamber;stop means for limiting the travel of said plunger with said piston andcausing the plunger to disengage from said piston when the volume of theworking chamber exceeds the predetermined maximum; said stop meanscomprising a stop pin mounted in the stem of said plunger on theopposite side of said end wall from said working chamber and engageablewith said end wall member; a main passage for conducting fluid underpresSure from a source to a fluid pressure operated device; a supplypassage connecting said main passage with the supply port of saidworking chamber; means operable to permit flow through said supplypassage only in response to fluid flow through said main passage; saidlast named means including a normally closed control valve in said mainpassage movable to an open position in response to a decrease in thepressure on the downstream side of said control valve with respect tothe pressure on the upstream side of said control valve; a normallyclosed supply valve in said supply passage movable to an open positionin response to fluid flow through the main passage past said controlvalve; means in said supply passage for adjustably restricting the flowthrough said supply passage to said working chamber; a return pressurebranch passage connecting the downstream portion of said main passagewith said bore on the opposite side of said piston from said workingchamber; said bore being stepped with a reduced portion located on theopposite side of said piston from said working chamber, said pistonhaving a reduced portion projecting into the reduced portion of saidbore, the reduced portion of said bore having an end wall cooperablewith the reduced portion of said piston to define a return pressurechamber, said return pressure branch passage extending between saidreturn pressure chamber and said main passage such that pressure in saidreturn pressure chamber urges said piston in the opposite direction tothe pressure in said working chamber; a pumping chamber having an intakeport adapted to be connected with a supply of lubricant and a deliveryport, and means operable to expand and contract said pumping chamber inresponse to movement of said piston in said bore.
 2. Lubricatingapparatus as claimed in claim 1 including a check valve controlling saidintake port movable to an open position in response to expansion of saidpump chamber to permit lubricant to be drawn into said pump chamber andmovable to a closed position in response to contraction of said pumpchamber; and a check valve controlling said delivery port movable to anopen position upon contraction of said pump chamber to permit lubricantto be delivered from said pump chamber, and movable to a closed positionin response to expansion of said pump chamber.
 3. Lubricating apparatusas claimed in claim 2 including a pumping plunger reciprocably mountedin said pump chamber and connected with said piston for expanding andcontracting said pump chamber in response to contraction and expansion,respectively, of said working chamber.
 4. Lubricating apparatus asclaimed in claim 3 wherein said pumping plunger has a stem projectinginto said return pressure chamber for engagement by said piston, andfurther including a spring in said pump chamber biasing said pumpingplunger to a position in which the pump chamber is expanded. 5.Lubricating apparatus comprising: an expansible and contractible pumpchamber having an intake port for connection with a supply of lubricantand a delivery port for delivering lubricant from said pump chamber; amain passage having an inlet for connection with a source of air underpressure and an outlet for connection with an air operated tool or thelike; a normally closed control valve controlling flow through said mainpassage and movable to an open position in response to a pressure dropbetween said inlet and outlet to permit flow through said main passage;and means operable in response to flow through said main passage tomechanically expand and contract said pump chamber continuously duringthe time that air flows through said main passage past said controlvalve.
 6. Lubricating apparatus as claimed in claim 5 further includingmeans for selectively varying the rate of expansion and contraction ofsaid pump chamber during flow through said main passage.
 7. Lubricatingapparatus as claimed in claim 5 wherein said means operable to cause thepump chamber to alternately expand aNd contract comprises a workingchamber and mechanism for causing said working chamber to alternatelyexpand and contract in response to flow through said main passage. 8.Lubricating apparatus as claimed in claim 7 including a cylindrical borewith an end wall member closing the open end thereof; and wherein saidmechanism includes a piston in said bore cooperable with said end wallmember to define said working chamber, said piston being movable towardand away from said end wall member to respectively contract and expandsaid working chamber.
 9. Lubricating apparatus as claimed in claim 8wherein said mechanism includes a control plunger mounted in said endwall member operable to cause said working chamber to vent and contractwhen the volume of the working chamber exceeds a predetermined maximum.10. Lubricating apparatus as claimed in claim 8 wherein said controlplunger has a stem portion slidably mounted in said end wall member andan enlarged end portion formed on said stem and received in said workingchamber and engageable with said piston.
 11. Lubricating apparatus asclaimed in claim 7 including a supply port for said working chamber; asupply passage connecting said supply port with said main passage; andmeans operable to permit flow through said supply passage only inresponse to fluid flow in said main passage.
 12. Lubricating apparatusas claimed in claim 11 wherein said last named means includes a normallyclosed supply valve controlling said supply passage and movable to anopen position in response to fluid flow through said main passage pastsaid control valve.
 13. Lubricating apparatus as claimed in claim 12further including means for selectively varying the rate of expansionand contraction of said pump chamber during flow through said mainpassage.
 14. Lubricating apparatus as claimed in claim 13 wherein saidlast named means comprises a needle valve in said supply passageadjustable to vary the rate of flow through said supply passage. 15.Lubricating apparatus comprising: a base member formed with a main airpassage having an inlet for connection with a source of air underpressure and an outlet for connection with an air driven tool or thelike; a normally closed control valve between said inlet and outletcontrolling flow through said main passage and movable to an openposition in response to a pressure drop between said inlet and outlet topermit flow through said main passage; a supply valve chamber formed insaid base member; a supply passage formed in said base member having oneend in communication with said supply valve chamber; a first branchpassage connecting said supply valve chamber with said control valve anda second branch passage connecting the supply valve chamber with thebranch chamber between the outlet and said control valve; a supply valvereceived in said supply valve chamber and having an open position topermit flow between said one branch passage and said supply passage anda closed position to shut off communication between said one branchpassage and said supply passage; said supply valve being biased to itsclosed position and responsive to a decrease in pressure in said secondbranch passage with respect to the pressure in said first branch passageto move to its open position; a return pressure passage formed in saidbase member communicating at one end with said main passage between theoutlet and control valve; a body member attached to said base member; apump chamber formed in said body member; a bore formed in said bodymember connected with the supply passage in said base member; and meansin said bore operable in response to flow through said supply passage tocause said pump chamber to alternately expand and contract. 16.Lubricating apparatus comprising: an expansible and contractible pumpchamber having an intake port for connection with a supply of lubricantand a delivery port for delivering lubricant from said pump chamber; amain passage having an inlet for connection with a source of air underpressure and an outlet for connection with an air operated tool or thelike; a normally closed control valve controlling flow through said mainpassage and movable to an open position in response to a pressure dropbetween said inlet and said outlet to permit flow through said mainpassage; means operable in response to flow through said main passage tocause said pump chamber to alternately expand and contract; said lastnamed means comprising a working chamber and mechanism for causing saidworking chamber to alternately expand and contract in response to flowthrough said main passage; a cylindrical bore with an end wall memberclosing the open end thereof; said mechanism including a piston in saidbore cooperable with said end wall member to define said workingchamber, said piston being movable toward and away from said end wallmember to respectively contract and expand said working chamber; saidcontrol plunger having a stem portion slidably mounted in said end wallmember and an enlarged end portion formed on said stem and received insaid working chamber and engageable with said piston, one face of saidpiston defining a movable wall for said working chamber; the enlargedend portion of said control plunger having a leading face engageablewith said one face of said piston and a trailing face projectinggenerally radially outwardly from said stem portion and subject toexpanding pressure in said working chamber when said leading face isengaged with said one face of said piston.
 17. Lubricating apparatus asclaimed in claim 16 including an abutment projecting from said end wallmember into said working chamber for engaging said trailing face tomaintain a space for fluid between said end wall and at least a portionof said trailing face.
 18. Lubricating apparatus as claimed in claim 17wherein a vent port is formed in said control plunger and one end ofsaid vent port communicates with said leading face.
 19. Lubricatingapparatus as claimed in claim 18 wherein the other end of said vent portcommunicates with a surface of said control plunger at a location spacedfrom said one end a distance such that said other end is uncovered bysaid end wall member only when said trailing face is engaged with saidabutment member.
 20. Lubricating apparatus as claimed in claim 19including a resilient sealing member secured to said one face of saidpiston for engagement by said leading face of said control plunger toseal off said vent port from said working chamber.
 21. Lubricatingapparatus as claimed in claim 19 including stop means for limiting thetravel of said plunger with said piston and causing the plunger todisengage from said piston when the volume of the working chamberexceeds the predetermined maximum.
 22. Lubricating apparatus as claimedin claim 21 wherein said stop means comprises a stop pin mounted in thestem of said plunger on the opposite side of said end wall from saidworking chamber and engageable with said end wall member.